Historically, a computer controlled cutting table incorporating a motor reciprocated knife has been used to cut a single-ply of flexible sheet type material, such as leather. For example, Zund Systemtechnik of Altstatten, Switzerland produces a motor reciprocated knife. A typical example of this type of cutting apparatus is schematically illustrated in FIG. 1.
In this example, a computer controlled tangent axis drive motor 1000 is coupled to a housing tube 1010 that is keyed to the reciprocating knife 1020. Therefore, any movement of the housing tube generates movement of the knife. The knife is oriented tangent to the cut path by rotating the housing tube via the tangent axis motor drive.
A limitation of the existing art is that the inertia of the housing tube is oriented along with the knife. This extra inertia may slow the angular acceleration of orientation of the knife. To maximize the throughput of cut pieces, it is desirable to orient the knife as quickly as possible.
Another difficulty occurs when multiple changes in the cutting direction of the knife is required at very short time intervals. A series of changes of cutting direction can decrease the quality of the final cut sheet by having the cutting knife's orientation hampered by the inertia of the housing tube. The use of the housing tube to orient the cutting knife can greatly and detrimentally affect the amount of time it takes to cut a pattern piece from the work material. In addition, because of the need for multiple changes in cutting knife direction, the likelihood for errors can increase at higher throughput speeds.
Based on the foregoing, there is a need in the art to provide a cutting apparatus that improves upon or overcomes the drawbacks of prior art devices.